Triangle of Ward numbers T(n,k) (n>=0, k=0 if n=0, otherwise 0 <= k <= n-1) read by rows.

Terms

a(0) =1a(1) =1a(2) =3a(3) =1a(4) =15a(5) =10a(6) =1a(7) =105a(8) =105a(9) =25a(10) =1a(11) =945a(12) =1260a(13) =490a(14) =56a(15) =1a(16) =10395a(17) =17325a(18) =9450a(19) =1918a(20) =119a(21) =1a(22) =135135a(23) =270270a(24) =190575a(25) =56980a(26) =6825a(27) =246a(28) =1a(29) =2027025